CVE-2019-1010260 in ktlint
Summary
by MITRE
Using ktlint to download and execute custom rulesets can result in arbitrary code execution as the served jars can be compromised by a MITM. This attack is exploitable via Man in the Middle of the HTTP connection to the artifact servers. This vulnerability appears to have been fixed in 0.30.0 and later; after commit 5e547b287d6c260d328a2cb658dbe6b7a7ff2261.
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Analysis
by VulDB Data Team • 08/21/2023
The vulnerability described in CVE-2019-1010260 represents a critical security flaw in the ktlint tool that enables arbitrary code execution through compromised artifact servers. This issue specifically affects the tool's ability to download and execute custom rulesets, creating a pathway for attackers to inject malicious code into the build process. The vulnerability stems from the insecure handling of HTTP connections during artifact retrieval, where ktlint fails to properly validate the integrity of downloaded jar files from remote repositories. This weakness directly impacts the security posture of development environments that rely on ktlint for code quality enforcement, as it allows malicious actors to compromise the tool's execution flow through compromised dependency servers.
The technical flaw manifests when ktlint attempts to fetch custom rulesets from remote artifact servers over unencrypted HTTP connections. This creates a prime opportunity for man-in-the-middle attacks where attackers can intercept and modify the downloaded jar files before they reach the target system. The vulnerability operates at the transport layer security level, exploiting the absence of proper certificate validation and integrity checking mechanisms during the artifact download process. According to CWE classification, this vulnerability aligns with CWE-319 - Cleartext Transmission of Sensitive Information, as it involves transmitting sensitive code artifacts over insecure channels. The flaw essentially allows an attacker to replace legitimate jar files with malicious ones that execute arbitrary code when loaded by ktlint.
The operational impact of this vulnerability extends beyond simple code quality enforcement, as it fundamentally compromises the integrity of the development pipeline. When exploited, the vulnerability enables attackers to execute arbitrary commands on systems running ktlint with compromised rulesets, potentially leading to full system compromise or data exfiltration. The attack vector requires only a man-in-the-middle position on the network path between the ktlint tool and the artifact servers, making it particularly dangerous in shared or untrusted network environments. This vulnerability affects organizations that use ktlint in automated build processes, continuous integration pipelines, or any scenario where the tool automatically downloads external dependencies without proper verification mechanisms. The implications are especially severe in enterprise environments where code quality tools are often run with elevated privileges or integrated into critical development workflows.
The fix implemented in ktlint version 0.30.0 addresses this vulnerability through enhanced security measures that prevent the execution of compromised artifacts. The resolution includes changes to how the tool handles artifact downloads, specifically addressing the commit referenced in the vulnerability description. Organizations should ensure they upgrade to version 0.30.0 or later to mitigate this risk, as the patch implements proper certificate validation and integrity checking for downloaded rulesets. Security teams should also consider implementing network-level protections such as certificate pinning, proxy configurations with SSL inspection, or network segmentation to further reduce the attack surface. This vulnerability highlights the importance of secure dependency management practices and demonstrates how seemingly innocuous development tools can become attack vectors when proper security controls are not implemented. The fix aligns with ATT&CK framework techniques related to privilege escalation and execution through legitimate user processes, as it prevents attackers from using the tool as a vector for code injection attacks.